A271419 If n is a ludic number, a(n)=0; if n is not a ludic number, a(n) is the ludic number that rejects n from the ludic number sieve.

0, 0, 0, 2, 0, 2, 0, 2, 3, 2, 0, 2, 0, 2, 3, 2, 0, 2, 5, 2, 3, 2, 0, 2, 0, 2, 3, 2, 0, 2, 7, 2, 3, 2, 5, 2, 0, 2, 3, 2, 0, 2, 0, 2, 3, 2, 0, 2, 5, 2, 3, 2, 0, 2, 11, 2, 3, 2, 7, 2, 0, 2, 3, 2, 5, 2, 0, 2, 3, 2, 0, 2, 13, 2, 3, 2, 0, 2, 5, 2, 3, 2, 0, 2, 7

Offset: 1

Author

Max Barrentine, Apr 07 2016

Keywords

• nonn

Links

• Max Barrentine, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A003309, A192607, A192490, A255127, A260738, A271420, A272565.

Cf. A264940 (analogous version for lucky numbers).

Programs

Scheme

(define (A271419 n) (* (- 1 (A192490 n)) (A272565 n))) ;; Antti Karttunen, Sep 11 2016

Formula

a(n) = (1-A192490(n)) * A272565(n). - Antti Karttunen, Sep 11 2016